航空遥感惯性稳定平台非线性摩擦建模与补偿

Nonlinear Friction Modeling and Adaptive Compensation on an Inertially Stabilized Platform System for Aerial Remote Sensing Application

为降低摩擦对航空遥感三轴惯性稳定平台高精度控制的影响,提出基于LuGre模型的惯性稳定平台反步积分自适应摩擦补偿方法。根据系统速度过零多值及位置'平顶'现象建立惯性稳定平台LuGre摩擦模型,利用两步辨识及动态参数优化方法得到系统摩擦模型参数,进而以李雅普诺夫稳定性理论为基础设计反步积分自适应摩擦补偿控制器。通过Matlab仿真分析摩擦对系统精度的影响,并与前馈补偿方法相比较,评价反步积分自适应补偿方法的有效性和鲁棒性。通过试验对某航空遥感惯性稳定平台方位系统进行摩擦模型及补偿方法验证。试验结果表明,反步积分自适应补偿能显著减小摩擦对系统的影响,使方位系统角位置误差波动范围、角位置跟踪方均根误差比未补偿前分别减少78.7%、91.5%,与仿真结果一致,对提高航空遥感三轴惯性稳定平台系统控制精度具有重要意义。

To decrease the influences of friction on control precision of a three-axis inertially stabilized platform （ISP） applied in the aerial remote sensing system, an adaptive backstepping control method based on the LuGre model is put forward. According to the characteristics of variable speed values over zero and flatheaded position, the LuGre model of a three-axis ISP is developed and parameters are identified through two-step and dynamic parameter optimization method. Then an adaptive backstepping controller is designed based on the theory of stability. The influences of friction on the precision of ISP＇s control system are analyzed by Matlab and compared with those of feedforward controller, the validity and robust of the controller are evaluated. Finally, to validate the proposed model and compensation method, the experiments are carried out to the yaw-gimbal system of an ISP. The results show that the adaptive backstepping method can significantly reduce the influences of friction on control precision, by which the fluctuation range error and the root-mean-square error of the angular position are decreased by 78.7% and 91.5% respectively.